1. Field of the Invention
The present invention relates to new disperse dyestuffs which may be used especially for the coloration of artificial or synthetic materials.
2. Summary of the Invention
The dyestuffs according to the present invention may be represented by the general formula: ##STR2## in which R.sub.1 represents hydrogen, halogen, nitro, alkyl or alkoxy and R.sub.2 represents hydrogen, halogen or cyano.
3. Description of the Preferred Embodiments
The halogen is preferably chlorine or bromine. The alkyl or alkoxy group which may be represented by R.sub.1 contains 1 to 4 carbon atoms and is preferably methyl, methoxy or ethoxy.
These compounds may be prepared by reacting the diazo derivative of an o-nitro-aniline of the formula: ##STR3## with a compound of the formula: ##STR4## in which formula R.sub.1 and R.sub.2 have the same significance as above and W represents an electro-attractor group which can be eliminated, for example an acyl group, especially an acetyl group.
The reaction of the diazo derivative of o-nitro-aniline of formula (II) with the compound of formula (III) is effected under the usual coupling conditions, the coupling component of formula (III) being able to be dissolved in water or in an organic solvent such as acetic acid.
The elimination of the group W is generally effected of itself during and/or after the coupling reaction, the speed of this elimination being a function of the substituents R.sub.1 and R.sub.2 and of the nature of the group W. In order to accelerate or possibly terminate the elimination of the group W, the reaction product may be taken up in an organic solvent such as, for example, acetic acid, methanol or ethanol, preferably at the boil.
The dyestuffs according to the invention are perfectly suitable for dyeing and printing all materials which can be dyed by disperse dyestuffs, especially those based on hydrophobic fibers such as polyurethane fibers, polyolefine fibers such as polypropylene either unmodified or modified by basic treatment or by treatment with nickel, cellulose diacetate or triacetate fibers and, above all, polyamide fibers such as Nylon-6, Nylon-6,6 and Nylon-12, aromatic polyesters such as those of terephthalic acid and ethylene glycol or 1,4-dimethylol-cyclohexane or mixed polymers of terephthalic and isophthalic acid with ethylene glycol.
The application of the dyestuffs according to the invention may be effected according to any known method of coloration by means of disperse dyestuffs.
Thus, for dyeing in aqueous baths, the dyestuffs according to the invention, insoluble or very sparingly soluble in water, are advantageously used in finely divided form and the operation is carried out in the presence of dispersants such as residual cellulose sulfite liquor or of synthetic detergents and of a combination of various wetting agents and dispersants. In general, it is advantageous to convert the dyestuffs to be used before their application into a tinctorial preparation, containing the dispersant and the finely divided dyestuff in a form such that by dilution of the preparation with water a fine dispersion is obtained. Such tinctorial preparations may be obtained in a known manner, for example by grinding the dyestuff in dry form or wetted, with or without addition of dispersants during this grinding. After wet grinding, tinctorial preparations containing textile auxiliary agents and the dyestuff are obtained by subsequent drying.
Examples of advantageous dispersants of the non-ionic category include the products of addition of 8 moles of ethylene oxide with 1 mole of p-tertio-octylphenol, 15 to 16 moles of ethylene oxide with castor oil, 20 moles of ethylene oxide with the alcohol C.sub.16 H.sub.33 OH, the products of addition of ethylene oxide with di-[.alpha.-phenylethyl]-phenols, the polyethylene oxide-tertio-dodecylthioethers, the polyamine-polyglycolethers, and the products of addition of 15 or 30 moles of ethylene oxide with one mole of dodecylamine or stearylamine.
Anionic dispersants which may be used include the sulfuric esters of fatty alcohols having 8 to 10 atoms of carbon, the sulfuric esters of the products of addition of ethylene oxide derived from the corresponding fatty amides or from alkylated phenols containing 8 to 12 carbon atoms in the alkyl residue, sulfonic esters containing alkyl residues having 8 to 20 carbon atoms, the sulfation products of fatty acids and unsaturated oils, the phosphoric esters containing alkyl residues having 8 to 20 carbon atoms, fatty acid soaps, the alkylarylsulfonates, the products of condensation of formaldehyde with naphthalenesulfonic acid and the sulfonates of lignin.
Suitable cationic dispersants are quaternary compounds of ammonium which contain alkyl residues or aralkyl residues having 8 to 20 carbon atoms.
The tinctorial preparations may also contain, in addition to dispersants, organic solvents, particularly those boiling above 100.degree. C., which are advantageously miscible with water, such as the mono- and di-alkyl-glycolethers, dioxan, dimethyl formamide or -acetamide, tetramethylene sulfone or dimethyl sulfoxide. It is advantageous to grind the dyestuff, the dispersant and the solvent together. One can also use only solvents alone in place of the dispersant, but the tinctorial preparations must contain either a dispersant or a solvent.
The dyeing of polyester fibers with the dyestuffs according to the invention is effected in aqueous dispersion according to the processes used for the polyesters. The polyesters of aromatic polycarboxylic acid and polyalcohol are preferably dyed at temperatures above 100.degree. C. and under pressure. The dyeing can also be effected at the boiling point of the dyebath in the presence of carriers such as, for example, polyphenols, compounds of diphenyl-polychlorobenzene, or analogous auxiliary products, or also according to the Thermosol process, that is, by foularding with subsequent heat treatment, for example, a heat fixation at 180.degree.-210.degree. C. The fibers of cellulose diacetate are advantageously dyed at temperatures of 80.degree. to 85.degree. C., while the fibers of cellulose triacetate are dyed at the boiling point of the dyebath. For dyeing cellulose diacetate or fibers of polyamides, it is unnecessary to use carriers.
For the heat-fixation of the dye, the foularded polyester fabric is heated, advantageously after previous drying, for example, in a current of hot air at temperatures exceeding 100.degree. C., advantageously between 180.degree. and 210.degree. C. The dyeings obtained may undergo a subsequent treatment, for example, by heating in an aqueous solution of a non-ionic detergent.
Instead of impregnation, the dyestuffs according to the invention may also be applied by printing. For this purpose, a printing color is used which contains, in addition to the usual auxiliary agents such as wetting agents and thickeners, the finely dispersed dyestuff.
The dyestuffs according to the invention may also be applied in a solvent medium, for example in perchlorethylene, alone or in admixture with 5-10% of dimethyl formamide or methanol.
With the dyes according to the invention, full-bodied dyeings and prints are obtained which have good fastness, especially to heat-fixing, sublimation, folding or creasing, flue gas, over-dyeing, dry cleaning, to chlorine and to wetting, for example to water, washing and perspiration.
The dyestuffs according to the invention may also be used for dyeing in bulk polyamide, polyester and polyolefin yarns. The polymer to be dyed is preferably mixed in the form of powder, grains, shavings, completely prepared solutions for spinning or in molten form, with the dyestuff which is incorporated in dry form or in the form of a dispersion or solution in a possibly volatile solvent. After homogenous distribution of the dye in the solution or in the molten mass of the polymer, the mixture is treated in a known manner by milling, pressure or extrusion, in order to obtain fibers, threads, filaments, films, etc. The dyestuffs according to the invention give deep and uniform colorations having good fastness to light and good general fastness.
The dyestuffs according to the invention are distinguished particularly by their good general properties of application (affinity and fastness to light) on polyester fibers.
In comparison with known dyestuffs. (French Pat. No. 1,410,212 (corresponding to U.S. Pat. No. 3,313,798) and Japanese patent application Nos. 72/31,926 and 73/19,871) which contain a heterocyclic residue (for example, benzimidazolyl) in place of the unsubstituted phenyl radical, the dyestuffs according to the invention have a better affinity for polyester fibers. Furthermore, the dyestuffs according to the invention are, on said fibers, faster to light than the compound of the formula: ##STR5## which is disclosed in the review Talanta 1970, 17 (2) pages 161-5 (see Chemical Abstracts vol. 72, 1970, No. 106721n) and is proposed as an acid-base indicator.